Instead of erroring out on unsupported pr_debug() (e.g., when patching a module), issue a warning and make it inert, similar to how unsupported tracepoints are currently handled.
Signed-off-by: Josh Poimboeuf <[email protected]> --- tools/objtool/klp-diff.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index d94632e80955..9ff65b01882b 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -1334,18 +1334,18 @@ static bool should_keep_special_sym(struct elf *elf, struct symbol *sym) * be applied after static branch/call init, resulting in code corruption. * * Validate a special section entry to avoid that. Note that an inert - * tracepoint is harmless enough, in that case just skip the entry and print a - * warning. Otherwise, return an error. + * tracepoint or pr_debug() is harmless enough, in that case just skip the + * entry and print a warning. Otherwise, return an error. * - * This is only a temporary limitation which will be fixed when livepatch adds - * support for submodules: fully self-contained modules which are embedded in - * the top-level livepatch module's data and which can be loaded on demand when - * their corresponding to-be-patched module gets loaded. Then klp relocs can - * be retired. + * TODO: This is only a temporary limitation which will be fixed when livepatch + * adds support for submodules: fully self-contained modules which are embedded + * in the top-level livepatch module's data and which can be loaded on demand + * when their corresponding to-be-patched module gets loaded. Then klp relocs + * can be retired. * * Return: * -1: error: validation failed - * 1: warning: tracepoint skipped + * 1: warning: disabled tracepoint or pr_debug() * 0: success */ static int validate_special_section_klp_reloc(struct elfs *e, struct symbol *sym) @@ -1403,6 +1403,13 @@ static int validate_special_section_klp_reloc(struct elfs *e, struct symbol *sym continue; } + if (strstr(reloc->sym->name, "__UNIQUE_ID_ddebug_")) { + WARN("%s: disabling unsupported pr_debug()", + code_sym->name); + ret = 1; + continue; + } + ERROR("%s+0x%lx: unsupported static branch key %s. Use static_key_enabled() instead", code_sym->name, code_offset, reloc->sym->name); return -1; -- 2.53.0
